SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06f91953fc67e58f496651cf7261b66cba92ab540d2fdcba2a59dcf970bb354c' 
  AND token = 'DTpN4+U8ppCgbYLVBPL/Jgq3x4OXN+ZhhVb75kQqfeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}